Nutrition Nuggets: High Blood Pressure, Part II

Posted 5/9/2013

Part II – Risk Factors

There are a number of dietary and lifestyle choices that contribute to the problem of elevated blood pressure. There are also things we have less control over.Hypertension frequently runs in families. It occurs more often among African Americans and those of Asian decent than among whites. High blood pressure can also result from kidney, thyroid, or adrenal gland disease or certain drugs including some oral contraceptives.

Excess Weight

As body weight increases, blood pressure rises as a greater volume of blood is required to supply oxygen and nutrients to all tissues. Your heart has to pump much harder to keep all living cells nourished if you’re overweight. Blood pressure is forced to rise in relation to the amount of excess weight that you have. Losing even 10 pounds can lower elevated blood pressure in those who are overweight. To a degree, the more excess weight you lose, the greater the drop is in blood pressure. Losing weight also makes blood pressure medications more effective.

Lack of Physical Activity

A lack of regular physical activity results in weak muscles throughout the body, including the heart. Consequently, the heart has to pump more frequently as it cannot contract as strongly as a trained muscle. As your heart rate increases, the harder your heart must work and the stronger the pressure is on your arteries. In contrast, the fit heart of a person who is physically active can pump more blood with less effort which decreases force on the arteries. Becoming more active can lower systolic pressure by an average of 4 to 9 points. These are the same results you would see using some blood pressure medications.

Smoking

The toxic chemicals associated with smoking are highly damaging. Up to an hour after just one cigarette, your blood pressure can be raised by 10 mm Hg or more. This increase in blood pressure is due to a combination of three physiologic responses: 1) Nicotine causes blood vessels throughout the body to constrict. This narrowing results in an increase in pressure of blood flowing through the arteries. 2) Nicotine speeds up the heart rate which simultaneously increases blood pressure.3) The carbon monoxide in tobacco smoke reduces the level of oxygen in the blood. With less available oxygen, the heart is forced to pump harder to supply the body with a sufficient amount, further raising blood pressure.

The Sodium/Potassium Connection

Recent surveys show that Americans consume about 3,300 mg of sodium (almost one and a half teaspoons of salt) per day which greatly exceeds the recommended level of no more than 2,300 mg. Most people get at least 75 percent of daily sodium from processed foods.

An increase in salt intake results in increased levels of blood pressure. As you may know, water is naturally drawn to sodium. When we consume excessive amounts of salt, our bodies retain water. Extra water increases our total volume of blood and this causes a rise in blood pressure. A potassium-rich diet helps to prevent sodium in the blood from getting too high. Potassium-rich fruits and vegetables include leafy greens, vine fruit, and root vegetables. The combination of high-salt intake coupled with low dietary potassium is an effective driver for high blood pressure. The standard diuretic medications given to control blood pressure have the effect of causing both sodium and potassium to be lost through urine. Consequently, patients starting diuretics are advised to increase their intake of potassium through diet or a supplement.

Alcohol Consumption

Drinking too much alcohol can raise blood pressure and damage vital organs such as the liver, brain, and heart. Alcoholic beverages are also high in calories. If you drink, limit yourself to no more than one a day for women or two for men. What counts as a drink?